The present invention relates primarily to the preparation of stained glass assemblies, and more specifically to the assembly of glass pieces into substantially self supporting two and three dimensional composites.
The conventional preparation of stained glass composites such as windows, panels and other three dimensional assemblies, includes, first of all, pattern making and cutting the individual glass pieces, generally flat glass pieces and then treating each piece by covering each edge either generally by attaching a copper foil strip having an adhesive on one side or enclosing each glass piece with channel shaped lead came. The cover generally overlaps both surfaces of the glass.
For a two dimensional panel, the treated glass pieces are arranged on a paper pattern, called a cartoon, and either soldered together where the lead came pieces intersect or, in the case of copper foil, bead soldered along all seams. In either case, the soldered panel is then turned over and solder applied to the second side in a like manner. In addition, where lead came is used, glazier's cement is applied to both sides of all channels to strengthen and weatherproof the panel. Furthermore, it is often necessary to employ an additional "saddle bar" support system for both lead and copper foil panels.
For three dimensional composites using the copper foil technique, the treated glass pieces are usually assembled on a mostly horizontal sectional mold and the outside bead soldered. The soldered section is then removed from the mold and the inside bead soldered. To complete the composite, the sections are soldered together on both inside and outside. For three dimensional composites using lead came, the treated glass pieces are assembled and soldered in a flat position then bent and joined to form a horizontal layer. Successive horizontal layers are assembled in a like manner then placed vertically, one on top of the other, and soldered together to form multiplanar composites. Also, it is often necessary to employ additional support members of both lead and copper foil for making three dimensional composites.
In addition to the methods of making joints between glass pieces, U.S. Pat. No. 4,252,847 to DelGrande discloses an adhesive layer being applied to the edges of the glass pieces which overlaps both surfaces of the glass. Metallic particles are then coated on the adhesive layer before it solidifies. The treated glass pieces are then laid on a cartoon or mold and the solder applied to both sides of the coated adhesive layer to form the joint.
In the case of three dimensional composites such as Tiffany type lamp shades, terrariums, boxes, etc., the flat pieces of glass are first cut to size and in many cases are temporarily placed on the surface of a form. In one example Crist in U.S. Pat. No. 4,557,772 discloses the pieces being temporarily attached to the external surface of a form and then joining the edges of the glass pieces together. However, in order to attach the glass pieces together, each piece of glass has to be removed and the edges covered or foiled and replaced. The solder is then applied to join the foiled edges together.
I have now found that I can perpare two dimensional and three dimensional configurations made from glass pieces which do not require the edges of the glass pieces to be covered by the application of foil or lead, and do not require the application of solder. The glass pieces my be bonded together using a bonding agent on the edges in a single step, the bonding agent not overlapping the surfaces of the glass pieces.
In most cases where glass composites are prepared, it is necessary to leave the cover or joining material overlapping the surfaces of the glass pieces. The application of a lead came or copper foil often requires heat which can result in breakage of the glass. In the case of lead joints, the resulting joint is flexible and has no structural strength, so stress fractures can occur in the glass pieces both in the assembly process, where the glass pieces are turned over before completion, and over time as the supporting system permits movement. There is no truly rigid system.
By utilizing a flexible material having an adhesive surface I can assemble uncovered glass pieces with spaces or gaps between edges of adjoining pieces for insertion of a bonding agent into a two dimensional configuration. In a three dimensional configuration, no spaces or gaps need be left. provided the assembly occurs on a flat plane and then the flexible material is then bent at the joins to form a three dimensional shape. The bend causes a V-groove for the insertion of a bonding agent and the bonding agent only joins the glass edges. The join is stronger than the glass which avoids stress cracks occurring in the glass. To increase the adhesive quanties of the bonding agent, for items such as aquariums, the smooth edges of the glass pieces may be roughened.
By utilizing a bonding agent I have found that I can prepare two and three dimensional glass composites with the joins between glass pieces being in any position, that is to say either vertical or horizontal. The bonding agent is in a putty like form which does not run as in the case of liquid solder. Furthermore, when applying the bonding agent to temporarily joined composites, both inside and outside faces of all joins are made at the same time. Also, the bonding agent forms a permanently weatherproof, watertight and non toxic seal that will not oxidize of decompose. In addition, this bonding agent allows for construction of substantially larger composites without requiring an additional support system. This is made possible due to a significant increase in tensile strength and significant reduction in weight of the bonding agent compared to present day methods employing heavy metals. I have also found that three dimensional multiplanar composites can now be assembled on full size vertical molds in one step. Furthermore, the process enables me to repair two dimensional or three dimensional composites of glass pieces by cutting out a damaged piece and replacing it without having to disassemble the composite or remove the damaged piece from an installed location.
The present invention provides a method of constructing a substantially self supporting composite of separate glass pieces comprising the steps of arranging a plurality of individual precut glass pieces with uncovered edges in a pattern with flexible material adhering to surfaces of adjacent glass pieces; providing gaps between the glass pieces to expose edges of adjacent glass pieces, and applying a bonding agent in the gaps to rigidly bond the edges between the adjaecnt glass pieces but not overlap onto the surfaces of the adjacent glass pieces.
The process may be carried out on two dimensional and three dimensional composites. The flexible material, which may be a sheet or strip overlapping adjacent edges of the glass pieces, may remain or alternatively can be removed after the bonding agent has hardened. A metallic power or other composition may be added to the top of the bonding agent, or if desired adhesive lead tape may be applied over the bonding agent thus showing leaded glass construction.